1. Field of the Invention
The present invention relates to a seat belt retractor system for a motor vehicle and a method of controlling a seat belt retractor system.
2. Background Art
Motor vehicles include seat belts for securing vehicle occupants. A seat belt retractor system may be used to actuate a seat belt to eliminate slack. Actuation of the seat belt may be accomplished by use of an electric motor. More specifically, a constant amount of voltage may be provided to rotate the motor and retract the seat belt at a constant rate. Larger motors and 42 volt vehicle electrical systems have been proposed to more rapidly retract a seat belt. Larger motors are undesirable due to their size and cost. 42 volt electrical systems are undesirable due to increased costs, complexity, as well as the need to redesign the entire vehicle electrical system.
Before Applicants' invention, a seat belt retractor system was needed that could retract a seat belt at one or more increased rates. In addition, a seat belt retractor system and a method of control was needed that could provide faster actuation, yet be compatible with conventional vehicle electrical systems. In addition, a system and method was needed that employed standard components and did not require additional package space. In addition, a system and method that was needed that could be easily implemented in high volumes and be compatible with vehicle assembly operations. Problems associated with the prior art as noted above and other problems are addressed by Applicants' invention as summarized below.